Maternal grandparents married Oct 1, 1892.Maternal grandmother’s parents were Frederick Kouse and his wife Louise. I have not found Louise’s maiden name.

Herbert Ralph Peterson was born in Chicago in 1919. In 1930 he is living in Chicago with his mother Florence Peterson, grandparents George and Emma Martha and aunt Evelyn Martha. Emma’s parents were born in Holland.

To prove that the Herb Peterson who was son of Florence Peterson, was the same one who invented the Egg McMuffin I used these records:According to the SSDI, a Florence Peterson, born in 1893, died in 1989. I cannot find her in the CA death index, but the SSDI says she last lived in Santa Barbara. The CA death index does list an Evelyn Martha who died in Santa Barbara, was born in Illinois in 1904, and whose mother’s maiden name is Kouse.

The 1880 census for Chicago has a record for Dutch-born Frederick Kause, wife Cornelia, dtr Emma, other children, and some stepkids named Prince. Emma was born in 1869 but Cornelia and Frederick married in 1873. KOUS, FREDERICK PRINCE, CORNELIA 06/11/1873 082/ 00010039 COOK

The 1870 census for Chicago has Frederick Cous (indexed as Cons on Ancestry), wife Louise, and dtr Emma.